The invention relates to nuclear magnetic resonance (NMR) spectroscopy, and more particularly relates to NMR spectroscopic analysis of liquid samples.
In conventional NMR spectroscopic analysis, a sample is placed in a sample tube and the sample tube is rotated at high speed (by a precision spinner turbine that is press-fit over the sample tube) so that the sample spins within the XY plane of the RF field. This is done because the sample is non-spherical and it is necessary that all parts of the sample be exposed to the average field flux. Without such rotation, the magnetic field gradients introduce artifacts in the NMR spectrum because the sample is non-spherical and all parts of the sample are not exposed to identical field strengths.
For certain applications, this has disadvantages. For example, it has been proposed to test human patients for cancer by taking a blood sample and subjecting it to NMR spectroscopic analysis. A dedicated machine which would be suitable for performing this function would be required to analyse many liquid samples, one after the other. If such testing were to be carried out by adapting existing technology, it would be necessary to e.g. repeatedly use the same sample tube or to use a plurality of sample tubes. Both approaches are not entirely satisfactory. The use of a plurality of sample tubes is unsatisfactory because of the time required to change samples and also because of the complicated apparatus needed to remove each sample tube and associated spinner turbine from the field region and to replace them with the next sample tube and spinner turbine. It is also unsatisfactory because spinner turbines are expensive. Reusing a single sample tube is likewise unsatisfactory because this requires manual handling or at least prolongs processing because of the number of process steps required. This can age the samples and introduce errors.
It would be advantageous to provide a device which would facilitate NMR spectroscopic analysis of a series of liquid samples.